OBD2 Fault Code Library

Free lookup for thousands of OBD2 trouble codes: filter by family, read short meanings, and open deeper articles. Desktop ELM327 scanner with live data and AI guidance.

OBD2 symptoms

Look up diagnostic trouble codes by what the car is doing: misfire, overheating, rough idle, a check engine light, and other common symptoms.

• Engine misfire
• Engine overheating
• Rough idle
• Check engine light
• Poor fuel economy
• Hard starting
• Engine stalling
• Catalytic converter efficiency
• Oxygen sensor fault
• EVAP leak
• Thermostat not reaching temperature
• Lean air-fuel mixture
• Rich air-fuel mixture
• EGR flow fault
• Engine knock
• Charging system
• Throttle position
• Mass airflow sensor
• Turbo underboost
• Coolant temperature sensor
• Transmission fault

• P0A09 — DC/DC Converter Status Circuit Low (P0A09): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, corroded, loose or damaged connector, open or shorted wiring in the circuit.
• P0A0A — High Voltage System Interlock Circuit (P0A0A): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P0A0B — High Voltage System Interlock Circuit Performance (P0A0B): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by open or shorted wiring in the circuit, corroded, loose or damaged connector, poor ground connection.
• P0A0C — High Voltage System Interlock Circuit Low (P0A0C): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by poor ground connection, blown fuse feeding the circuit, control module driver fault.
• P0A0D — High Voltage System Interlock Circuit High (P0A0D): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, faulty sensor or actuator of the affected circuit, poor ground connection.
• P0A0E — OBD2 code P0A0E flags a problem with the sensor and actuator circuits (high voltage system interlock circuit intermittent). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, corroded, loose or damaged connector, blown fuse feeding the circuit.
• P0A0F — OBD2 code P0A0F flags a problem with the sensor and actuator circuits (engine failed to start). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, blown fuse feeding the circuit, poor ground connection.
• P0A10 — DC/DC Converter Status Circuit High (P0A10): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by open or shorted wiring in the circuit, blown fuse feeding the circuit, poor ground connection.
• P0A11 — OBD2 code P0A11 flags a problem with the sensor and actuator circuits (DC/DC converter enable circuit/open). The car is usually drivable while you plan the repair. Common culprits: faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector, open or shorted wiring in the circuit.
• P0A12 — OBD2 code P0A12 flags a problem with the sensor and actuator circuits (DC/DC converter enable circuit low). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
• P0A13 — DC/DC Converter Enable Circuit High (P0A13): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, faulty sensor or actuator of the affected circuit, poor ground connection.
• P0A14 — Engine Mount "A" Control Circuit/Open (P0A14): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit, poor ground connection.
• P0A15 — Engine Mount "A" Control Circuit Low (P0A15): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by open or shorted wiring in the circuit, blown fuse feeding the circuit, corroded, loose or damaged connector.
• P0A16 — P0A16 — Engine Mount "A" Control Circuit High. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, blown fuse feeding the circuit, poor ground connection.
• P0A17 — OBD2 code P0A17 flags a problem with the sensor and actuator circuits (motor torque sensor circuit). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, poor ground connection, control module driver fault.
• P0A18 — OBD2 code P0A18 flags a problem with the sensor and actuator circuits (motor torque sensor circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, corroded, loose or damaged connector, poor ground connection.
• P0A19 — OBD2 code P0A19 flags a problem with the sensor and actuator circuits (motor torque sensor circuit low). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, corroded, loose or damaged connector, poor ground connection.
• P0A1A — OBD2 code P0A1A flags a problem with the sensor and actuator circuits (generator control module). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, faulty sensor or actuator of the affected circuit, control module driver fault.
• P0A1B — OBD2 code P0A1B flags a problem with the sensor and actuator circuits (drive motor "A" control module). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• P0A1C — Drive Motor "B" Control Module (P0A1C): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by corroded, loose or damaged connector, poor ground connection, faulty sensor or actuator of the affected circuit.
• P0A1D — OBD2 code P0A1D flags a problem with the sensor and actuator circuits (hybrid powertrain control module). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, corroded, loose or damaged connector, open or shorted wiring in the circuit.
• P0A1E — Starter/Generator Control Module (P0A1E): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit.
• P0A1F — OBD2 code P0A1F flags a problem with the sensor and actuator circuits (battery energy control module). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, corroded, loose or damaged connector, open or shorted wiring in the circuit.
• P0A20 — P0A20 — Motor Torque Sensor Circuit High. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, poor ground connection, open or shorted wiring in the circuit.